I have a problem or might not be a problem just a situation I just wanted to check on.

Whenever the A/C Compressor clutch kicks in (about every 5 seconds) my battery guage drops. it drops about 1 volt -/+. I just wanted to see if this happens to anyone else.

94 Jeep Grand Cherokee limited 5.2L

Mine also does it, and I'm almost positive that it is the AC Clutch. If I'm rolling down the highway it's alright, but if I'm stopped it will occasionally start to squeal and then the volts really drop.

An AC clutch is almost as much as a whole new compressor, so it's a catch -22 as far as which way to go to fix it. Does anyone know on here a cheaper way to fix the clutch than spending ~$200 for a new one?

Thanks,
Nathan

I don't think it's really a problem, the squealing you hear is prolly from the belt going bad, it is prolly stretched out too far and causing slippage when the excess tension is applied by the clutch. I just modified my belt tensioner to add some tension b/c the tensioer was maxed out and would not keep enough tension, and I too had the belt squeal when the clutch would kick in, but now I don't do to the modification of the tensioner.

I have another thing going on tooo..

my A/C blows cold air for the first few seconds then gets warm, I check the charge witht he guage and it's right in the full marks.

also...
whenever I have the A/C running and I shut the jeep off, I hear a leaking sound, I dunno if this is normal or if it is an actual leak, could someone check theirs as well?

Hi guys,

As McKoy might say, "Dammit Jim, I'm an electricain, not an HVAV guy!" But here's my take -

Your volts dropping a bit when the clutch engages is understandable, it's a big electromagnet powered by your alternator. On my XJ, it did the same thing. I wouldn't worry about it.

The leaking sound I believe is freon (and oil) leaking past the orifice at the output side of the compressor. If I understand the operation of HVAC, we compress the gasses which in effect 'presses' the heat out, and as the gas passes from the high pressure side of an orifice (small restriction) to the low pressure side, it expands soaking up heat from the surrounding area. I don't think that hissing is a huge deal, I think it's just gas equalizing on the two sides of the orifice, but like I say, I don't know for sure. Why would it blow hot after startup, well, I just don't know...

:2cents:

If your clutch is kicking in every 5 seconds your system innt up to charge.Thats most probally it blows cold and then hot. Try adding about a half a can to a can to see if the clutch stays on. The system should get colder. Make sure you put the AC on high and try putting a fan in front of the radiator like a window fan to help with the air flow.

If your clutch is kicking in every 5 seconds your system innt up to charge.Thats most probally it blows cold and then hot. Try adding about a half a can to a can to see if the clutch stays on. The system should get colder. Make sure you put the AC on high and try putting a fan in front of the radiator like a window fan to help with the air flow.


I will try this, I was worried about adding more, when I checked it with my guage it was in the FULL range (4 ranges, low, full, alert and danger). But I will try to add a bit more and see if it help, I just didn't want to hurt anything by adding too much.

To understand it you need gauge readings as in 24lbs on low side to maybe 220 - 240 0n high side depending on outside temp at the time. Idle engine up and low side should drop to around 24 lbs when it gets down to teens it will cut off and turn back on at around 42lbs. Now this is low side readings. The noise is the system equalizing after shut down. The compressor should not cycle every 5 seconds.

Hi,

I seem to have a similar problem without the voltage fluctuation. My compressor cycles on and off about once every 5 seconds. I added a charge without any change in the cycling, but the air (which was blowing warm) began coming out cool again. It lasted about two days. I began to wonder if I had a leak in the system. The R-134 which I added had the red die in it. I investigated all of the lines and do not find any trace of die. However, I do notice that when I run the A/C the low pressure line (where you add charge) is freezing cold.

Now, it is my understanding that this line runs to the evaporator and then back to the condensor. The lines coming into and leaving the condensor in the engine compartment are both warm. I remember these lines always being cold when the system was working properly. Despite the low pressure line coming from the compressor being ice cold, the air still blows warm.

I do not want to add any more charge because this seems odd to me. Is it possible that there could be a clog in the evaporator in the cabin preventing the refigerant from traveling through it? If I had a leak big enough to cause such an abrupt change in temperature, I would think that I could: 1. see the die some place, or 2. that the low pressure line would not be ice cold.

Any ideas?

Okay I will try to guide you. Starting at the compressor, the line that runs from there to condensor is a high side or called liquid line. From condensor headed to the evaperator is also high until you get to the orifice. Now the orifice is place in different places during the years. Some are inbeded in the high side line from condensor to evaperator. Sometimes the orifice is in the evaperator where freon goes in. This also is a smaller line. The small service port is the low side and the bigger service port is the high side. Now for the yearts where the orifice is inbeded in the line, the line before orifiec [ high side ] will be hot. After the orifice the line will be cold [low side]. The big line leaving evaperator goes to the accumulator. From accumulator to compressor. This is low side, notice larger line. The compressor should maintain about 24lbs on low side at 1800 rpms with very little clucth cycles. And the hardest thing to find leak in is the evaperator. It is in the heater/ac housing so very hard to get to. Need electronic leak detector to help find theses leaks.

I just checked my lines and the low line (where you add the charge) going into the firewall is freezing cold while the other line coming out of the firewall is not cold at all.

Well that will be somewhat true. The line coming out has warm up some because the freon is taking heat out. But what are your pressures? The line should still be on the cold side. The line that is going in is smaller than the line coming out. The line coming out goes to the accumulator [ the silver tank ]. Then it leaves there for the compressor.

murpht3, I had the same exact issues with my AC I recharged it friday and today I have no A/C, the air coming out is warm/cool, nothing like it was the friday and saturday.

rksnc, The line coming out of the firewalll is warm to the touch, not cool/cold at all. The LOW Side pressure is about 28 PSI then goes up to about 59 PSI then the clutch kicks in and the pressure drops back down to about 28 PSI.

Thank you skrnc for the response. I notice the same symptoms as dksob81. I always remembered the return line to the accumulator being cool to the touch. Now it is warm, almost hot to the touch. Do you think this is symptomatic of a leak or another problem?

Okay now what is the high side doing during this time. Both reading are important. If I had to guess with only low side readings and the responce you are getting I would say it is still low on freon. Where is the high side readings? And for info , this system is running what is refered to as a flooded evaperator. If line coming out is warm i would think then that we don't have enough freon to take in all the heat. What freon is in the system is taking as much heat as it can. You have to understand how it works, to make sense of it. Let me know the high side readings too.

Evaporator is known to leak on the ZJ's. Had mine replaced last year. It was still under warranty. Dash has to come out and it seems like they also pulled my center console because when I got it back the plastic trim around the emergency brake handle was broken off and the console was loose and missing 2 screws. They also broke the antenna wire. Dealer only on new antenna. I work on residential and commercial HVAC. I used an electronic detector to locate leak. There is a small hole in the glove box, that's where I would get reads from with the detector. According to the service manager at the dealership you should be able to see dye where the evaporator drain tube is or on the ground.

That is true. I see bad evap in Jeeps all the time. And yes the complete dash has to be remove just to start getting at the evap. I use electronic leak detector at the vents. On the newer Jeeps theses days you can;t get to drain. The drain comes out in frame down in the corner. But when drains are there, which is on most vehicles. I look for dye, when I have put it into system. I also use the leak detector there also. And on vehicles that you can remove blower resistor great place too. Now having the right light to make dye more visable helps too.

Okay now what is the high side doing during this time. Both reading are important. If I had to guess with only low side readings and the responce you are getting I would say it is still low on freon. Where is the high side readings? And for info , this system is running what is refered to as a flooded evaperator. If line coming out is warm i would think then that we don't have enough freon to take in all the heat. What freon is in the system is taking as much heat as it can. You have to understand how it works, to make sense of it. Let me know the high side readings too.


I will take the high side reading 2morow morning and let you know.

I can't test the HIGH SIDE with my guage, it won't fit ont he HIGH SIDE port..

Most of the kits that you buy only come with 1 gauge. It's intended to be used on the low side. The purpose of using different size fittings is to prevent someone from trying to connect a can of 134 to the high side. A set of gauges with connections for both low, high and vacuum/fill sells at JCWhitney for 99.00. I'm sure you can find them for a little less. My puron manifold set was expensive, fortunately my company bought them.

well this is a lil late but.

My reading are, at 72 degrees farenheit (ambient tempature).
Low - 35 PSI.
High - 245 PSI.

Could anyoe tell me what the problem is?

Well with those readings thing should not be that bad. The low side is a little high. Now I am thinking theses are the readings while engine is running oh around 15 to 2000 rpms. I would like to see low side aroung 27. At 35 the temp at that line should be 35 or 38 deg. Pressure and temp are close to the same. Should check heater control valve and make should that it is closing and stopping flow of water when ac on.

Well with those readings thing should not be that bad. The low side is a little high. Now I am thinking theses are the readings while engine is running oh around 15 to 2000 rpms. I would like to see low side aroung 27. At 35 the temp at that line should be 35 or 38 deg. Pressure and temp are close to the same. Should check heater control valve and make should that it is closing and stopping flow of water when ac on.

These reading were taken with engine idling @ about 600 RPM's.

where is the high side ? (i have 96 JGC 4.0)

is that the upper tube that has the connection near the windshield ?

the high side is connected to the AC Compressor itself (on my 94 5.2L, I am sure it is located on the same on yours), the low side is on the passenger side by the coolant bottle..

I don't think it's really a problem, the squealing you hear is prolly from the belt going bad, it is prolly stretched out too far and causing slippage when the excess tension is applied by the clutch. I just modified my belt tensioner to add some tension b/c the tensioer was maxed out and would not keep enough tension, and I too had the belt squeal when the clutch would kick in, but now I don't do to the modification of the tensioner.
dksob81,
My sqealing belt persists even after I changed it. I mean, the sqealing stopped for a day or two, but when I a) turn corners with b) the air/heat/fan on, then it sqeals. I also find that it sqeals when I c) accelerate from a stop with b) the air/heat/fan on. I have a 94 4.0L, meaning that adjusting the belt is a real treat (ugh!). Thanks for your insight. Thanks also for your work in keeping this forum such a great resource!

Cheers!

dksob81,
My sqealing belt persists even after I changed it. I mean, the sqealing stopped for a day or two, but when I a) turn corners with b) the air/heat/fan on, then it sqeals. I also find that it sqeals when I c) accelerate from a stop with b) the air/heat/fan on. I have a 94 4.0L, meaning that adjusting the belt is a real treat (ugh!). Thanks for your insight. Thanks also for your work in keeping this forum such a great resource!

Cheers!

How tight is the belt? I know what you mean, I do not see why they did not make an self-adjusting tensioner for the 4.0L.

What brand of belt did you use, I have had very good luck with the GoodYear GatorBack belts, they are very good belts and are just about guarenteed to get rid of squealing.
Let me explain a lil bit: about 2 years ago my belt broken (one of the ribs broke and was flapping around hitting off of everything) and when I heard the belt flapping around I pulled over (right in front of one of my local GM Garages) and bout a new belt, it was an exact fit for my 5.2 it was 1 rib short (a lil thinner) than the original but I just needed it to get by for a few days, well it would squeal real bad in the morning and whenever the engine was cold. I replaced it with another one dayco brand and a couple days later it started squealing, replaced it once more with another brand (don't remember which brand) and same thing after a couple days it started squealing, then someone told me about the GoodYear Gatorback, so I decided what the hay might as well change it, b/c it got real annoying listening to that squealing every morning and it didn't look so good for my jeep. Well to that day (about a month ago, when I wrecked my jeep) it did not squeal once in about the last 2 years.

Well, when I went in to get my belt, I asked for the best. Guess what I was given? The Goodyear Gatorback. It is quite a handsome belt, to be sure!
I must say, the squealing overall is far below what it used to be, It would squeal by simply driving down the road, but not now! To prevent the squealing that remains when I turn corners with the heat/air on, I wonder if I should release tension on the belt or tighten it?
Thanks, this forum is great, I've recommended it to several Jeep owners...

Well, when I went in to get my belt, I asked for the best. Guess what I was given? The Goodyear Gatorback. It is quite a handsome belt, to be sure!
I must say, the squealing overall is far below what it used to be, It would squeal by simply driving down the road, but not now! To prevent the squealing that remains when I turn corners with the heat/air on, I wonder if I should release tension on the belt or tighten it?
Thanks, this forum is great, I've recommended it to several Jeep owners...

I would try tightening the belt up just a hair and see what that does.